Non-terminal epoxy phenolic ester monomers and resins thereof



United States Patent 3,305,564 N ON-TERMINAL EPOXY PHENOLIC ESTER MONOMERS AND RESINS THEREOF William S. Port, Norristown, and Daria M. Ostapiak, Philadelphia, Pa., assignors to the United States of America as represented by the Secretary of Agriculture N0 Drawing. Filed Mar. 27, 1961, Ser. No. 98,717

' 7 Claims. (Cl. 260--348) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to non-terminal epoxy resins pre pared from a novel group of epoxy monomers.

Commercially available intermediates for thermo-setting resins, useful in molding compositions for encapsulating delicate parts, making shaped objects, and the like, are frequently glycidyl derivatives or contain terminal epoxide groups. Processes have been developed in which epoxy ether resin and com-positions containing these resins are mixed with curing (hardening) agents and, usually with slight heating, allowed to stand until a hard, cured resin is produced. In contrast to the foregoing type of epoxy resin, compounds containing non-terminal epoxides, many of which have been known for many years, are little used because these compounds are less reactive and because the cured resins derived therefrom have low heat distortion temperatures, low tensile strengths, and low moduli of elasticity. A high heat distortion temperature is an important property for many of the uses to which one may wish to apply these resins.

In our US. Patent No. 2,975,149, it is demonstrated that non-terminal epoxides such as epoxidized vegetable oils, epoxidized animal oils, and epoxidation products of esters prepared from unsaturated long carbon chain fatty acids and mon-o-, di-, and polyhydric short carbon chain saturated aliphatic alcohols were among those which produced useful resins when heated with a cyclic anhydride in the presence of a tertiary amine. In those non-terminal epoxy resins it will be noted that the heat distortion temperature of the resin product varies directly with the number of epoxy functions in the monomer in both the epoxidized oleate and epoxidated linoleate series, and that, in general, a considerable number of epoxy functions in the monomer is necessary to provide a resin with relatively high heat distortion temperature.

We have found that changing the source of the central nucleus of the monomer from a saturated aliphatic polyol such as ethylene glycol to a polyphenol such as catechol, resorcinol and hydroquinone, results in resins with improved heat distortion temperatures.

In general, according to the present invention a compound of the general formula 1 is obtained by preparing the catechol, resorcinol and hydroquinone esters of oleic and linoleic acids and then epoxidizing the ester, and a resin is prepared by combin ing the compound with an amount ranging from one epoxide equivalent to :20% of one epoxide equivalent per molecule of a cyclic carboxylic anhydride such as phthalic anhydride and with about 0.1 to 4% by weight of the final mixture of a tertiary amine such as benzyldi-methylamine, ,B-dimethylaminopropionitrile or triamylamine, and heating the mixture to effect polymerization.

The resin products, ranging in physical property from flexible to stiff, all have heat distortion temperatures 40 to degrees higher than corresponding resins prepared from glycol esters.

The preparation of an ester is illustrated in the following example.

EXAMPLE 1 Preparation of catechol di0leate.-Catechol (11 grams, 0.1 mole) was dissolved in 30 grams of pyridine and 61.4 grams (0.202 mole) of oleoyl chloride was slowly added during the course of 1% hours at temperatures in the range of 10 to 32 C. The reaction mixture was then heated to 120 C. and maintained at this temperature for about 1 /2 hours. The reaction mixture was cooled to room temperature, poured into water, and the aqueous layer was discarded. Ether, 250 ml., was added and the ethereal solution was extracted with 2% aqueous sodium hydroxide, then washed free from alkali with water and dried over anhydrous calcium sulfate. The solvent was distilled off at reduced pressure. The residue weighed 56 grams (87.6% yield) and had an iodine number of 79.2 (theory 79.6).

TABLE I Reactants Products Product Analysis Ex. Yield Carbon Hydrogen Iodine Number No.

Diphenol G. Acid G. Name Chloride G Per- Cale. Found Calc. Found Cale. Found cent 1. Catechol 11 Oleoyl. 61. 4 Catcchol dioleate 56 88 78. 94 78. 82 11. 04 11. 18 79. 4 79. 2 2. Resorcinol 11 do".-. e7 Resorcinol dioleate 57 89 78. 94 77.98 11. 04 11. 29 79. 4 81. s 3..." I-Iydroquinone 11 73.7 lIydroquinone (1ioleate 13. 5 39 78. 94 78.88 11. 04 10. 93 79. 4 7h. 0 4. Catechol 7. 15 LinoleoyL 41. 7 Catecliol dilinoleate 17. 6 42 70. 44 78.97 10.48 10. 159. 9 155. 6 5. Resorcinol. 10. 5 v. d0 92. 5 Resorcinol dilinoleate 82. 6 87 79. 44 77. 97 10. 48 10. 57 159. 9 159. 0 6. IIydroquiuone 16. 5 .110..." 92. 5 Hydroquinone dillnoleate (i1. 0 64 79. 44 79.21 10.48 10. 86 159. 9 156.8

8 Vinyl oleate.

A procedure similar to that of Example 1 was employed to prepare the compound of Examples 2, 4, and 6 of Table I. In Example 3 is described a different procedure for making an oleate ester.

EXAMPLE 3 Preparation of catechol bis-(9,10-ep0xystearvzte).To 50 grams catechol dioleate dissolved in 150 m1. chloroform was added 45 grams peracetic acid (35% peracetic acid in acetic acid) containing 2.24 grams sodium acetate while the reaction mixture was stirred and maintained at a temperature between 2535 C. After 3 /2 hours of reaction, the mixture was poured into about 300 ml. of cold water and the chloroform layer was separated. The chloroform layer was washed successively with dilute sodium bicarbonate solution and water until neutral and then dried. The chloroform was distilled off under reduced pressure and the residue (37 grams) was recrystallized from 370 ml. of acetone. The yield of catechol Cir tion did not appreciably change the heat distortion temperature of the resin products.

A practical time-temperature relationship for reaction of the ingredients was determined by preliminary experimentation. As typified in Example 13, an initial temperature of 150 C., followed by curing at 120 C. for about 24 hours, gave resins whose heat distortion temperature did not appreciably improve upon further curing. When lower temperatures are used the reaction time must be increased to achieve a resin with about the same physical properties.

The tertiary amine was added at the level of 2.5% by weight of the resin ingredients in the preparation of these cured resins, but a range of levels of addition of from about 0.1 to 4% of tertiary amine is applicable to the process.

EXAMPLE 13 A solution of 3.39 grams catechol bis-(9,10-epoxystearate), the monomer of Example 7, 1.48 grams phthalic anhydride, and 0.122 grams benzyldimethylamine was heated at 150 C. Gelation occurred in 3% hours. The polymeric product was further heated for 3 hours at 150 C. and for 24- hours at 120 C. The cured resin had a heat distortion temperature of 13 C., tensile strength of 1100 lbs/square inch, and tensile modulus of 1.05 10 lbs/square inch.

In a similar manner the monomers of Examples 8 to 12 were processed into cured resins, and the data pertaining to reactants and physical properties of the resulting resins are included as Examples 14 to 18 along with Example 13 in Table III.

TABLE I11 lteaetants Resin Properties Example Nurnbe Product of Table II Phthalic Benzyl- Heat; Tensile Tensile Anhydride, dirnethyl- Distortion Strength, Modulus,

g. amine, g. Temp, C. lbs/sq. in. lbs/sq. in. Exam plo No. G. 10'

bis-(9,10-epoxystearate), analyzing 4.74% oxirane oxygen content, was 29 grams (55% yield).

Of the cured resins of the present invention, the products of Examples 13 to 15 were flexible materials and TABLE II Reactants Analysis Example Product of Product Carbon Hydrogen Oxirane Oxygen N umber Table I 35% Yield Melting Peracetie Point, Acid, g. C. Example G. G. Per- Cale. Found Cale. Found Cale. Found N umber cent;

In a similar fashion the esters of Examples 2 to 6 were those of Examples 16 to 18 were hard, stiff materials, making them useful for a variety of purposes. Upon comparison of the heat distortion temperatures of these resins with those obtained from epoxidized glycol dioleate and epoxidized glycol dilinoleate in application Serial No. 796,710 now US. Patent No. 2,975,149, there is a difference in the resins from epoxidized glycol dioleate at 29 C. and the epoxidized dioleates of the present application (ranging from 13 to 23 C.) of 40 to 50 degrees. A similar increase in heat distortion temperature is found upon comparing the resin from epoxidized glycol dilinoleate (80 C.) with the epoxidized dilinoleates of the present invention (123-131 C.). Since the only difference in the respective monomers is the moiety to which the epoxidized fatty acids are attached, the enhancement of heat distortion temperature can be attributed directly to the introduction of an aromatic nucleus into the present monomers.

We claim:

1. A compound of the general formula 6 Catechol bis-(9,10-epoxystearate). Resorcinol bis-(9,10-epoxystearate).

Hydroquinone bis-(9,IO-epoxystearate). Catechol bis-(9,10;12,13-diepoxystearate). Resorcinol bis-(9,10; l2, 13-diepoxystearate). Hydroquinone bis-(9,10;12,13-diepoxystearate).

References Cited by the Examiner UNITED STATES PATENTS 2,786,066 3/1957 Frostick et a1 2602 2,786,067 3/1957 Frostick et a1 2602 2,970,983 2/ 1961 Newey 26047 2,978,463 4/1961 Kuester et a1. 26034 FOREIGN PATENTS 1,085,872 7/1960 Germany.

OTHER REFERENCES Swift: Australian Abstract 59,642/ 60, October 27, 1960.

WALTER A. MODANCE, Primary Examiner.

MAURICE A. BRINDISI, Examiner.

NORMA S. MILESTONE, ARTHUR L. LIBERMAN, Assistant Examiners. 

1. A COMPOUND OF THE GENERAL FORMULA 